EMTP Applications, Laboratory III, April – May, 2001
HÁLÓZATI TRANZIENSEINEK
SZÁMÍTÓGÉPI SZIMULÁCIÓJA
VILLAMOSENERGIA-RENDSZEREK FÕSZAKIRÁNY
LABOR III.
MÉRÉSVEZETÕ:
PRIKLER LÁSZLÓ
TARTALOMJEGYZÉK
OLDAL
1. AZ ATP-EMTP SZIMULÁCIÓS PROGRAMCSOMAG ÁTTEKINTÉSE
1
2. ATPDRAW GRAFIKUS FELHASZNALÓI INTERFACE
6
3. HÁLÓZATANALÍZIS AZ IDÕ- VAGY FREKVENCIA-TARTOMÁNYBAN
17
4. TÁVVEZETÉKEK ÉS KÁBEL SZIMULÁCIÓJA
21
5. TIPIKUS ALKALMAZÁSI PÉLDÁK
22
6. A LABORATÓRIUMI MÉRÉS SORÁN ELVÉGZENDÕ FELADATOK
30
2001 ÁPRILIS - MÁJUS
EMTP Applications Laboratory, April - May, 2001
ATP simulation package
Capabilities of the Transients Program ATP-EMTP
ATP-EMTP as world-wide mostly used universal program for digital simulation of
electromagnetic transients in power systems has extensive modelling capabilities. Besides actual
simulation module there exist several non-simulation supporting routines, which can be used to
generate model data like computation of line parameters or derivation of coupled RL matrix to
represent multi-phase, multi-winding transformers in the time-domain simulation.
A schematic overview of available simulation modules and supporting routines and their
interaction is shown below.
Prof. Dr. Kizilcay
page 1
EMTP Applications Laboratory, April - May, 2001
ATP simulation package
Built-in Electrical Components
Component type
LINEAR BRANCHES
NONLINEAR BRANCHES
Prof. Dr. Kizilcay
ATP Element Identification
‚ type 0 : Uncoupled lumped series RLC element
‚ type 1,2,3,.. : Mutually coupled ð-circuit
‚ type 51,52,53,.. : Mutually coupled RL elements
‚ type -1,-2,-3,.. : Distributed parameter line models
• Constant parameter line model (Clark, K.C. Lee)
• Special double-circuit distributed line
• SEMLYEN line model
• JMARTI line model
• NODA line model
‚ Saturable TRANSFORMER component (multi winding)
• TRANSFORMER single-phase units
• TRANSFORMER THREE PHASE with zero-sequence coupling
• IDEAL TRANSFORMER component
• BCTRAN supporting routine
• KIZILCAY F-DEPENDENT (high order admittance branch)
• CASCADED PI - type 1,2,3 element (for steady-state solution)
• PHASOR BRANCH [Y] - type 51,52,53 element
(for steady-state solution and Frequency Scan computation)
‚ type 99 :
‚ type 98 :
‚ type 97 :
‚ type 96 :
‚ type 94 :
‚ type 93 :
‚ type 92 :
Pseudo-nonlinear resistance
Pseudo-nonlinear inductance
Staircase time-varying resistance
Pseudo-nonlinear hysteretic inductor
User-defined component via MODELS
True, nonlinear inductance
– Exponential ZnO surge arrester
– Multi-phase, piece-wise linear resistance with
flashover
‚ type 91 : Multi-phase time-varying resistance
TACS/MODELS controlled resistance
‚ User supplied Fortran nonlinear element
page 2
EMTP Applications Laboratory, April - May, 2001
Component type
ATP simulation package
ATP Element Identification
‚ type 0 : Stand alone switches
• Time-controlled switch
• Voltage-controlled switch
• MEASURING switch
SWITCHES
‚ type 0 : Statistical switches
• STATISTICS switch
• SYSTEMATIC switch
‚ TACS/MODELS controlled switch
• type 11 : Switch for diode and thyristor application
• type 12 : Switch for spark gap and triac application
• type 13 : Simple TACS/MODELS controlled switch
‚ Empirical Sources
SOURCES
‚ Analytical Sources (voltage or current)
• type 11 : Step function
• type 12 : Ramp function
• type 13 : Two-slope linearized surge function
• type 14 : Cosine function / trapped charge
• type 15 : Exponential surge function
• type 16 : Simplified AC/DC converter model
• type 18 : Ideal transformer / ungrounded voltage source
‚ TACS/MODELS controlled sources
• TACS/MODELS modulation
• TACS/MODELS controlled voltage/current source
‚ Rotating Machines
• type 59 : Three-phase synchronous machine
(prediction method)
• type 58 : Three-phase synchronous machine
(phase-domain solution)
• type 19 : Universal Machine model
USER-DEFINED
COMPONENTS
‚ type 94 : MODELS controlled electrical branch
• Thevenin type model
• Iterated type model
• Non-transmission Norton type model
• Transmission Norton type model
EMTP Applications Laboratory, April - May, 2001
ATP simulation package
Simulation Modules
MODELS in ATP is a general-purpose description language supported by a large set of
simulation tools for the representation and study of time-variant systems.
% The description of each model is enabled using free-format, keyword-driven syntax of local
context and that is largely self-documenting.
% MODELS allows the description of arbitrary user-defined control and electric circuit
components, providing a simple interface for connecting other programs/models to ATP.
% As a general-purpose programmable tool, MODELS can be used for processing simulation
results either in the frequency domain or in the time domain.
TACS is a simulation module for time-domain analysis of control systems. It was originally
developed for the simulation of HVDC converter controls. In TACS block diagram
representation of control systems is used. TACS can be used for the simulation of
%
%
%
%
HVDC converter controls
Excitation systems of synchronous machines
power electronics and drives
electric arcs (circuit breaker and fault arcs).
Interface between electrical network and TACS is established by exchange of signals like node
voltage, switch current, switch status, time-varying resistance, voltage and current sources.
Important Supporting Programs
LINE CONSTANTS is a supporting routine to compute electrical parameters of overhead
lines in frequency-domain like per length impedance and capacitance matrices, ð-equivalent,
model data for constant-parameter distributed line (CPDL) branch. LINE CONSTANTS in ATP
is internally called to generate frequency data for the line models SEMLYEN SETUP, JMARTI
SETUP and NODA SETUP.
CABLE CONSTANTS / CABLE PARAMETERS are supporting routines to compute
electrical parameters of power cables. CABLE PARAMETERS is newer than CABLE
CONSTANTS and has additional features like handling of conductors of arbitrary shape, snaking
of a cable system and distributed shunt admittance model. CABLE CONSTANTS is linked to
SEMLYEN SETUP and JMARTI SETUP whereas CABLE PARAMETERS is called by NODA
Prof. Dr. Kizilcay
page 4
EMTP Applications Laboratory, April - May, 2001
ATP simulation package
SETUP to generate frequency-dependent electrical parameters.
SEMLYEN SETUP is a supporting routine to generate frequency-dependent model data for
overhead lines and cables. Modal theory is used to represent unbalanced lines in timedomain.Modal propagation step response and surge admittance are approximated by second
order rational functions with real poles and zeros.
JMARTI SETUP generates high-order frequency-dependent model for overhead lines and
cables. The fitting of modal propagation function and surge impedance is performed by
asymthotic approximation of the magnitude by means of a rational function with real poles.
JMARTI line model is not suitable to represent cables.
BCTRAN is an integrated supporting program in the ATP-EMTP, that can be used to derive a
linear [R], [ L] or [A], [R] matrix representation for a single- or three-phase transformer using
data of the excitation test and short-circuit test at rated frequency. For three-phase transformers,
both the shell-type (low homopolar reluctance) and the core-type (high homopolar reluctance)
transformers can be handled by the routine.
XFORMER is used to derive a linear representation for single-phase, 2- and 3- winding
transformers by means of RL coupled branches. BCTRAN should be preferred to XFORMER.
SATURA is a conversion routine to derive flux-current saturation curve from either RMS
voltage-current characteristic or current-incremental inductance characteristic. Flux-current
saturation curve is used to model a non-linear inductance, e.g. for transformer modeling.
ATPDraw has this feature integrated in the model Saturable 3 phase transformer.
ZNO FITTER can be used to derive a true non-linear representation (typ-92 branches) for a
zinc-oxide surge arrester, starting from manufacturer's data. ZNO FITTER approximates
manufacturer's data (voltage-current characteristic) by a series of exponential functions of type
i ' p@
v
Vref
q
.
DATA BASE MODULE allows the user to modularize network sections. Any module may
contain several circuit elements. Some data, such as node names or numerical data may have
fixed values inside the module, whereas other data can be treated as parameters that will be
passed to the data base module, when the module is connected to the data case via $INCLUDE.
Prof. Dr. Kizilcay
page 5
EMTP Applications Laboratory, April – May,2001
ATPDraw
ATPDraw the graphical front-end interface
Introduction
The ATP-EMTP simulation system consists of various separate supporting programs (pre- and
post processors), data initialization files and the solver program (TPBIG.EXE). ATPDraw can
be used as a simulation center, that provides an operating shell for other ATP-EMTP
components. This shell function is supported by version 1.2 and above [1].
Fig. 1 gives a functional overview of the traditional use of ATP-EMTP program. Program
components are communicating via disk files: i.e. the output of the pre-processors are used as
input for the main program, while the product of the simulation can be used as input for
plotting programs. When the main program is used as pre-processor for some components
(e.g. BCTRAN, LINE CONSTANTS etc.), the punch file products must be re-used as input in
a subsequent run. The structure of the program components is rather difficult, so having a user
shell which supervises the execution of separate programs and input/output flows has a great
advantage.
ASCII Text
editor
TPPLOT
PCPLOT
.ADP
project file
.ATP file
input data
PlotXY
.ALC
line data
USP
Library
ATPDraw
*.PL4
graphical
user-shell
*.PS
LCC
PCPLOT for
Windows
PL42mat
.PCH
Library
*.ATP
GTPPLOT
ATP
(TPBIG.EXE)
Data
Information
.PL4, .PS,
.HGL file
DspATP32
DisplayNT
Fig. 1 - Schematic description of the ATPDraw user shell
L. Prikler
page 6
Introduction
1 What is ATPDraw?
ATPDraw for Windows is a graphical, mouse-driven preprocessor to the ATP version of the
Electromagnetic Transients Program (EMTP). It assists to create and edit the model of the
electrical network to be simulated, interactively. In the program the user can construct an electric
circuit, by selecting predefined components from an extensive palette. The preprocessor then
creates the corresponding ATP input file, automatically in correct format. Circuit node naming is
administrated by ATPDraw and the user only needs to give name to "key" nodes. ATPDraw
currently supports about 70 standard components and 28 TACS objects. A simplified usage of
MODELS is also possible. In addition, the user can create his own circuit objects using the Data
Base Module and the $INCLUDE option of ATP. Both single phase and 3-phase circuits can be
constructed. Multiple circuit windows are supported to work on several circuits simultaneously
and copy information between the circuits. Most types of edit facilities like copy/paste, rotate,
import/export, group/ungroup, undo and print are available. Other facilities in ATPDraw are: a
built-in editor for ATP-file editing, support of Windows clipboard for bitmap/metafile, output of
Windows Metafile/Bitmap file format or PostScript files.
ATPDraw is most valuable to new users of ATP and is an excellent tool for educational purposes.
It is to be hoped, however that even experienced users of ATP will find the program useful for
documentation of circuits and exchanging data cases with other users. The possibility of building
up libraries of circuits and sub-circuits makes ATPDraw a powerful tool in transients analysis of
electric power systems. The ATPDraw package also includes the ATP_LCC program for
Line/Cable constants support and a utility, that makes possible the usage of existing circuit files
created by the previous (DOS/GIGS) versions of the program under the new environment.
The program is written in Borland Pascal. Two functionally very similar versions of ATPDraw
exist. A 32-bit version which is written in Borland Delphi 2.0 runs only under Windows 95/NT
and a 16-bit version compiled with Borland Delphi 1.0 for Windows 3.x.
ATPDraw is a trademark and copyrighted by © 1996-1997 SINTEF Energy Research,
Trondheim, Norway. It is programmed and maintained by Dr. Hans Kr. Høidalen. The program
was redesigned and converted to Windows by O. G. Dahl, Dahl Data Design, Norway.
The ATPDraw for Windows program is royalty free. The proprietary rights of the program belong
to the Bonneville Power Administration, USA, the company who financed the development.
2 Short description of ATP
ATP (Alternative Transients Program) is considered to be one of the most widely used software
for digital simulation of transient phenomena of electromagnetic, as well as electromechanical
nature in electric power systems. It has been continuously developed through international
contributions over the past 20 years, coordinated by the Canadian/American EMTP Users Group
co-chaired by Drs. W. Scott Meyer and Tsu-huei Liu.
ATPDraw version 1 for Window
7
Introduction
The ATP program calculates variables of interest within electric power networks as functions of
time, typically initiated by some disturbances. Basically, the trapezoidal rule of integration is used
to solve the differential equations of system components in the time domain. Non-zero initial
conditions can be determined either automatically by a steady-state, phasor solution or they can be
entered by the user for some components.
ATP has many models including rotating machines, transformers, surge arresters, transmission
lines and cables. With this digital program, complex networks of arbitrary structure can be
simulated. Analysis of control systems, power electronics equipment and components with
nonlinear characteristics such as arcs and corona are also possible. Symmetric or unsymmetric
disturbances are allowed, such as faults, lightning surges, any kind of switching operations
including commutation of valves. Calculation of the frequency response of phasor networks is
also supported.
ATP includes at present the following components:
Uncoupled and coupled linear, lumped elements.
Transmission lines and cables with distributed and frequency-dependent parameters.
Elements with nonlinearities: transformers including saturation and hysteresis, surge
arresters, arcs.
Ordinary switches, time-dependent and voltage-dependent switches, statistical switching
Valves (diodes and thyristors).
3-phase synchronous machines, universal machines.
MODELS and TACS (Transient Analysis of Control Systems).
MODELS in ATP is a general-purpose description language supported by an extensive set of
simulation tools for the representation and study of time-variant systems. MODELS allows the
description of arbitrary user-defined control and circuit components, providing a simple interface
for connecting other programs/models to ATP. As a general-purpose programmable tool,
MODELS can be used for processing simulation results either in the frequency domain or in the
time domain.
The following supporting routines are available in ATP:
LINE CONSTANTS, CABLE CONSTANTS and CABLE PARAMETERS for calculation
of electrical parameters of overhead lines and cables
Generation of frequency-dependent line model input data: JMARTI Setup, SEMLYEN
Setup and NODA Setup.
Calculation of model data for transformers (XFORMER and BCTRAN).
Saturation and hysteresis curve conversion.
Data Base Modularization
ATP is available for most Intel based PC platforms under DOS, Windows 3.x/95/NT, OS/2, Linux
and for other computers, too (e.g., Digital Unix and VMS, Apple Mac’s, etc.). The program is in
principle royalty free, but requires a license agreement signed by the requester and the
Canadian/American EMTP Users Group, or the authorized regional users group representatives.
ATPDraw version 1 for Windows
8
Introductory Manual
This part of the manual gives the basic information on how to get started with ATPDraw.
The Introductory Manual starts with the explanation of how to operate windows and mouse in
ATPDraw. The manual shows how to build a circuit step by step, starting from scratch. Then
special considerations concerning three phase circuits are outlined.
3 Operating Windows
ATPDraw has a standard Windows user interface. This chapter explains some of the basic
functionalities of the Main menu and the Component selection menu, and two important windows:
the Main window and the Component dialog box.
The Main window
Main menu
Tool bar icons
Component
tool bar
Windows
standard buttons
Circuit
map
Header,
circuit file
name
Circuit
windows
Scroll
bars
Circuit
comments
Current
action
mode
Status
bar
with
menu option hints
Component
selection menu
Fig. 3.1 - The Main window. Multiple Circuit windows and the floating Selection menu.
The ATPDraw for Windows program has a functionality similar to the DOS version . The
Component selection menu is hidden, however, but appears immediately when you click the right
mouse in the open area of the Circuit window. Fig. 3.1 shows the main window of ATPDraw
containing two open circuit windows. ATPDraw supports multiple documents and offers the user
ATPDraw version 1 for Windows
9
Introductory Manual
to work on several circuits simultaneously along with the facility to copy information between the
circuits. The size of the circuit window is much larger than the actual screen, as it is indicated by
the scroll bars of each circuit window. The Main window consists of the following parts:
Header + Frame:
As a standard Windows element, it contains the system menu on the left side, a header text and
minimize, maximize, exit buttons on the right side. The main window is resizeable.
System menu:
Contains possible window actions: Close, Resize, Restore, Move, Minimize,
Maximize or Resize and Next. The last one exists only if multiple circuit
windows are open.
Header text:
The header text is the program name in case of the main window and the
current circuit file name in case of the circuit window(s). To move a window,
click in the header text field, hold down and drag.
Minimize button: A click on this button will iconize the main window.
Maximize button: A click on this button will maximize the window. The maximize button will
then be replaced with a resize button. One more click on this button will bring
the window back to its previous size.
Corners:
Click on the corner, hold down and drag to resize the window.
Main menu:
The main menu provides access to all the functions offered by ATPDraw. The menu items are
explained in detail in the reference part of this manual:
File:
Edit:
View:
ATP:
Objects:
Tools:
Window:
Help:
Load and save circuit files, start a new one, import/export circuit files, create
postscript and metafile/bitmap files, print the current circuit and exit.
Circuit editing:copy/paste/delete/duplicate/flip/rotate, select, move label, copy
graphics to clipboard and undo/redo etc.
Tool bar, status bar and comment line on/off, zoom, refresh and view options.
Create node names, make ATP file, edit ATP file, ATP file settings (miscellaneous
cards and file formats, file sorting etc.), running batch jobs.
Edit support files (default values, min/max limits, icon and help file), create new files
for MODELS and User Specified Objects.
Icon editor, help file editor, text editor, setting of various program options.
Arranging of the circuit windows. Map window.
About box and Windows help file system.
Circuit window:
The circuit is built up in this window. The circuit window is the container of circuit objects. From
the file menu you can load circuit objects from disk or simply create an empty window to start
building a new circuit. Circuit objects include standard ATP components, user specified elements,
MODELS and TACS components, connections and relations. To move around in the circuit, you
can use the window scrollbars, or drag the view rectangle of the Map window to another position.
Component selection menu:
This menu is hidden initially and pops-up only after a right mouse button click in an empty space
of the Circuit window. In this menu all circuit objects can be selected. After selecting an object in
one of the fields or pop-up menus, the object is drawn in the circuit window in marked and
moveable mode.
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10
Introductory Manual
Circuit comments:
A comment line below the circuit window shows a user defined circuit comment text.
MAP window:
This window gives a bird's eye view of the entire circuit. The size of a circuit is 5000x5000 pixels
(screen points); much larger than your screen would normally support. Consequently, the Circuit
window displays only a small portion of the circuit. The actual circuit window is represented by a
rectangle in the Map window.
Press and hold down the left mouse button in the map rectangle to move around in the map. When
you release the mouse button, the circuit window displays the part of the circuit defined by the
new rectangle size and position. The map window is a stay-on-top window, meaning that it will
always be displayed on the top of other windows. You can show or hide the map selecting the
Map Window option in the Window menu, or pressing the M character,
Status bar - Action mode field:
The current action mode of the active circuit window is displayed in the status bar at the bottom of
the main window, when the Status Bar option is activated in the View menu. ATPDraw can be in
various action modes. The normal mode of operation is MODE : EDIT , in which new objects are
selected and data are given to objects. Drawing connections brings ATPDraw into CONN.END
mode and so on. ATPDraw’s possible action modes are:
EDIT
CONN.END
MOVE LABEL
GROUP
INFO.START
INFO.END
The normal mode.
After a click on a node, the action mode turns into CONN.END indicating that
the program is waiting for a left mouse click to set the end-point of a new
connection. To cancel drawing a connection, click the right mouse button or
press the ESC key to return to MODE : EDIT.
Indicates a text label move. Clicking the left mouse button on a text label, then
holding it down and dragging it enables you to move the label to a new
position. If the text label is overlapped by a component icon, the text label can
be moved using Move Label in the Edit menu. Then the action mode turns into
MOVE LABEL. Releasing the mouse at the new text label location, the action
mode returns to MODE : EDIT.
Indicates region selection. Double clicking the left mouse button in an empty
space of the active circuit window enables you to draw a polygon shaped
region. To end the selection, click the right mouse button. Any objects within
the selected region are marked then for selection. To cancel region selection,
press the Esc key.
Indicates the start of a relation when TACS | Draw relation is activated in the
selection menu. Clicking the left mouse button on a component node or on the
end-point of another relation will initiate the drawing of a new relation.
Relations are used to visualize information flow into FORTRAN statements
and are drawn as blue connections, but do not influence the connections of
components. To cancel, click the right mouse button or press the Esc key.
Indicates the end of a relation. The program is waiting for a left mouse button
click to set the end-point of the new relation. To cancel drawing relation, click
the right mouse button or press the Esc key.
ATPDraw version 1 for Windows
11
Introductory Manual
Status bar - Modified and Hints field:
The middle field of the status bar is used to display the Modified state of the active circuit. As
soon as you alter the circuit (moving a label, deleting a connection, inserting a new component,
etc.), the text 'Modified' appears, indicating that the circuit must be saved before exit. The field
will be empty when you save the circuit or undo all modifications. The rightmost field of the
status bar displays the menu option hints.
The Component dialog box
After selecting a component in the Component selection menu the new circuit object appears in
the middle of the circuit window enclosed by a rectangle. Click on it with the left mouse button to
move, or the right button to rotate, finally click in the open space to unselect and place the object.
The object input window appears when you click the right mouse button (or double click with the
left button) on a circuit object. Assuming you have clicked on the icon of an RLC element, a
dialog box shown in Fig. 3.2 appears.
Fig. 3.2 - The Component dialog box.
The Component dialog box has the same layout for all circuit objects. In this window the user
must specify the required component data. The number of DATA and NODES menu fields are the
only difference between input windows for standard objects. The nonlinear branch components
have a Characteristic page too, in addition to the normal Attributes page, where the nonlinear
characteristics and some include file options can be specified.
Carriage return, Tab or the mouse can be used to move the cursor between input fields. The arrow
keys can be used to move the cursor inside of a menu field. When the cursor is moved out to the
right side of the field the menu content is scrolled.
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12
Introductory Manual
Numerical values in the data input windows can be specified as real or integer, with an optional
exponential integer, identified by ‘E’ or ‘e’. An “Illegal numeric specification” message is
produced, when the characters are non-numeric. Legal formats are: 3.23e4, 323E+02, 32300,
32.3e+3 etc.
Input texts in the node input menus can be specified with any characters (remember that characters
like * - + / $ etc. should not be used in ATP node names, also avoid space and lower case letters).
The user does not need to give names to nodes, in general. The name of the nodes without special
interest are recommended to be left unspecified. ATPDraw will then give a unique name to those
nodes. The node dot of these nodes are displayed in red color in the circuit window.
Below the data input column there is a Group No input field. This is an integer field where an
optional group number can be specified to the object, which could be used as a sorting criteria (the
lowest group number will be written first into the ATP file).
Below the node input column there is a Label input text field. The content of this field is written
on the screen and also into the circuit file. The label text is movable. The component dialog box
has a Comment input text field. If you specify a text in this field, it will be written to the ATP file
as a comment (i.e. as the first line of the object’s data).
The radio buttons of the Output group specify the branch output requests. If the Hide box is
selected, the object becomes hidden (which means that it is not written to the ATP file) and its
icon becomes light gray in the circuit window. The Lock option is not yet implemented in the
present version of the program.
The OK button will close the dialog box and the object’s data and its properties are updated in the
data structure. The red drawing color which indicates that no data is given to the object will be
turned off. When you click on the Cancel button, the window will be closed without updating the
object’s data. The Help button invokes the Help Viewer showing the help text of the object. For
obtaining further help press the F1 key.
4 Operating the mouse
This chapter contains a summary of the various actions taken dependent on mouse operations. The
left mouse button is generally used for selecting objects or connecting nodes; the right mouse
button is used for specification of object or node properties.
Left simple click:
On object:
Selects object (also connection).
If the Shift key is pressed, the object is added to the current group.
On object node:
Begins to draw a connection.
Moves the mouse to the end node, left click to place, right to cancel.
In the open area of the circuit window:
Unselects object.
Right simple click:
On object node:
ATPDraw version 1 for Windows
13
Introductory Manual
Opens the node dialog box.
On unselected object:
Opens the component dialog box.
On unselected object, when you hold down the Shift key:
Opens the circuit window shortcut menu.
On selected object(s):
Rotates object(s).
In the open area of the circuit window:
Cancels connection made.
Left click and hold:
On object:
Moves object(s).
On node:
Resizes connection (it is often necessary to select connection first).
In the open area of the circuit window:
Draws a rectangle for group selection.
Objects inside the rectangle become a group when the mouse button is released.
Left double click:
On object node:
Performs the Node dialog box.
On unselected object:
Performs the Component dialog box.
On selected object:
Performs a Group Number specification window.
In the open area of the circuit window:
Starts the group selection facility. Click left to create corners in an enclosing polygon,
click right to close. Objects inside the polygon become a group.
5 Edit operations
ATPDraw offers the most common edit operations like copy, paste, duplicate, rotate and delete.
The edit options operate on a single object or on a group of objects. Objects must be selected
before any edit operations can be performed. Selected objects can also be exported to a disk file
and any circuit files can be imported into another circuit.
Tool
Shortcut key
Equivalent in menus
Copy
Ctrl+C
Edit | Copy
Paste
Ctrl+V
Edit | Paste
Duplicate
Ctrl+D
Edit | Duplicate
Rotate
Ctrl+R
Edit | Rotate (or right click)
Flip
Ctrl+F
Edit | Flip
Group
Ctrl+G
Edit | Select group (or left double click in open space)
All
Ctrl+A
Edit | Select All
Label
Ctrl+L
Edit | Move Label
UNDO
Alt + BkSp
Edit | Undo
REDO
Shft+Alt+BkSp Edit | Redo
Zoom In/Out
+/View | Zoom In / Out
Zoom window Z
View | Zoom
ATPDraw version 1 for Windows
14
Introductory Manual
The ground symbol is drawn at the selected node when you exit the window as Fig. 3.3 shows.
The nodes not given a name by the user will automatically be given a name by ATPDraw, starting
with XX followed by a four digit number. Nodes got the name this way (i.e. from the program) are
distinguished by red color from the user specified node names.
Fig. 3.3 - Click on the voltage source node with the right mouse button
and specify the source node name.
6 Storing the circuit file
You can store the circuit in a disk file whenever you like during the building process. This is done
in the main menu with File | Save (or Ctrl+S). If the current circuit is a new one which has not
been previously saved, a Save As dialog box appears where you can specify the circuit name. Two
different styles of the Save As dialog boxes are available, depending on the Open/Save dialog
setting in the Tools | Options | General menu: a Windows 95 standard dialog box and a Windows
3.1 style. The default extension is .CIR in both cases and it is automatically added to the file name
you have specified.
When the circuit once was saved, the name of the disk file appears in the header field of the circuit
window. Then if you hit Ctrl+S or press the Save circuit icon in the Toolbar, the circuit file is
updated immediately on the disk. The File + Save As option or the Save As icon from the Toolbar
allows the user to save the circuit currently in use under a name other than that already allocated to
this circuit.
7 Creating ATP file
The ATP file is the file required by ATP to simulate a circuit. The ATP file is created by selecting
Make File command in the ATP main menu.
Before you create the ATP file, you must specify some miscellaneous parameters (i.e. parameters,
that are printed to Misc. Data card(s) of the ATP input file). The default values of these
parameters are given in the ATPDraw.ini file. Changing these default values can either be done
in the Settings | Simulation sub-menu under the ATP main menu for the current circuit, or under
the Tools | Options | View/ATP | Edit settings for all new circuits created henceforth.
Fig. 3.4 shows an example of the ATP’s 1st miscellaneous data card settings (specifying time
step, time scale of the simulation etc.). This window appears if you select the Simulation tab of the
ATP | Settings menu.
ATPDraw version 1 for Windows
15
Introductory Manual
Select:
Time step T in sec.
End time of simulation Tmax in sec.
Xopt=0: Inductance in mH.
Copt=0: Capacitance in F.
Press Help to get more information or OK
to close the dialog box.
The simulation settings are stored in the
circuit file, so you should save the file after
changing these settings.
Fig. 3.4 Simulation settings.
The first integer miscellaneous data card is changed under the ATP | Settings | Integer page, and
the statistic/systematic switch control card is specified under the ATP | Settings | Switch settings.
Under the File format page the user can
select precision mode and the ATP-file
sorting criteria. The main characteristic of
the simulation (time domain or frequency
scan) can also be set on this page. If you
select the File format page, the window
shown in Fig. 3.5 appears:
Select:
Sorting by cards: First /BRANCH, then
/SWITCH and then /SOURCE.
All other check boxes are unselected
Fig. 3.5 - The file format menu.
To create an ATP file you must select the Make File in the ATP menu. This selection will start a
procedure which examines your circuit and gives node names to circuit nodes. Then a standard
Windows’ Save As file window appears, where you can specify the name and path of the ATP file.
The same name as the circuit file with extension .ATP is suggested.
You can load an old circuit whenever you like (select File | Open) and create the corresponding
ATP file (select ATP | Make File).
ATPDraw version 1 for Windows
16
Solution Methods in ATP
The time-domain and frequency-domain solution methods in ATP will be reviewed briefly.
Detailed analysis of numerical modeling of system components and electrical networks are given
in the EMTP Theory Book (TB). The review focuses rather to the applicational features and
limitations of the solution methods.
Time-domain solution methods
The electric network is described in ATP-EMTP using node equations, i.e. node voltages are
selected as state variables. Branch currents are expressed therefore as functions of the node
voltages.
The solution for each element in time-domain is performed using time step discretization. The
value of all system variables are supposed to be known at t – t and their value is to be
determined at time t. The time step t is assumed to be so small that the differential equations are
approximated by difference equations.
For example, a simple algebraic relationship is obtained by replacing the differential equation for
a inductance
v
L di
(1)
dt
with a central difference equation that is equivalent to the numerical integration of i using
trapezoidal rule for one time step.
v(t)
v(tt) L i(t) i(tt)
2
i(t)
with G
Gv(t) Ihist(t –t)
t
(2)
(3)
t . G is the equivalent conductance that remains constant, when the time step t of
2L
the computation is constant. Ihist(t – t) is the history term composed of know quantities from the
Prof. Dr. Kizilcay
17
preceding time step having the unit of Ampere. A similar formulation can be written for capacitor
and resistors. For multi-phase coupled elements this basic formulation still holds. The equations
of multi-phase coupled elements are incorporated into the nodal admittance matrix of the
electrical network.
For any type of network with n nodes, a system of n such equations can be formed1,
[G] [v(t)] [i(t)] [Ihist]
with
(4)
[G] : n x n symmetric nodal conductance matrix,
[v(t)] : vector of n node voltages,
[i(t)] : vector of n current sources, and
[Ihist] : vector of n known "history" terms.
Normally, some nodes have known voltages either because voltage sources are connected to
them, or because the node is grounded. In this case Eq. (4) is partitioned into a set A of nodes
with unknown voltages, and a set B of nodes with known voltages. The unknown voltages are
then found by solving
[GAA] [vA(t)]
[iA(t)] [Ihist A] [GAB] [vB(t)]
(5)
for [vA(t)].
The actual computation in the EMTP proceeds as follows: Matrices [GAA] and [GAB] are
built, and [GAA] is triangularized with ordered elimination and exploitation of sparsity. In each
time step, the vector on the right-hand side of Eq. (5) is updated from known history terms, and
known current and voltage sources. Then the system of linear equations is solved for [vA(t)],
using the information contained in the triangularized conductance matrix. In this "repeat
solution" process, the symmetry of the matrix is exploited in the sense that the same
triangularized matrix used for downward operations is also used in the backsubstitution. Before
proceeding to the next time step, the history terms included in [IhistA] are then updated for use in
future time steps.
The transient simulation can be started from
1) zero initial conditions
2) a.c. steady-state initial conditions at a given frequency.
1
Brackets are used to indicate matrix and vector quantities.
Prof. Dr. Kizilcay
18
Frequency-domain Solution Methods
Frequency-domain solution methods implemented in ATP are based on the a.c. steady-state
solution of the linear network. Nodal equations are written using complex phasor quantities for
currents and node voltages. For any type of network with n nodes, a system of n such equations
can be formed,
[Y] [V]
with
[I]
(10)
[Y] : symmetric nodal admittance matrix, with complex elements,
[V] : vector of n node voltages (complex phasor values),
[I] : vector of n current sources (complex phasor values).
Eq. (10) is partitioned into a set A of nodes with unknown voltages, and a set B of nodes with
known voltages. The unknown voltages are then found by solving the system of linear, algebraic
equations
[YAA] [VA]
[IA] [YAB] [VB]
(11)
Bringing the term [YAB][VB] from the left-hand side in Eq. (10) to the right-hand side in Eq. (11)
is the generalization of converting Thevenin equivalent circuits (voltage vector [VB] behind
admittance matrix [YAB]) into Norton equivalent circuits (current vector [YAB][VB] in parallel
with admittance matrix [YAB]).
FREQUENCY SCAN Feature
The FREQUENCY SCAN (FS) feature of the ATP allows for the repetition of steady-state phasor
solutions, as the frequency of sinusoidal sources is automatically incremented between a
beginning and an ending frequency. Rather than conventional time-response output, a frequencyresponse output of desired quantities like node voltage, branch current or driving-point
impedance/admittance is obtained. When plotted, the time axis of conventional ATP simulations
becomes the frequency axis, with the result being a frequency curve. Either polar coordinates
(magnitude and angle) or rectangular coordinates (real and imaginary parts) of the phasor
solution variables are used for output purposes.
Typical applications of the FREQUENCY SCAN are:
Analysis and identification of resonant frequencies of power networks and individual system
components;
19
Computation of frequency response of driving-point network impedances or admittances seen
from a busbar, for example, positive-sequence or zero-sequence impedance;
Analysis of harmonics propagation in a power system using extended feature Harmonic
Frequency Scan (This subject will be handled in detail separately).
HARMONIC FREQUENCY SCAN (HFS) Feature
HFS is a companion to Frequency Scan (FS). Both FS and HFS performs a series of phasor
solutions. FS solves the network for the specified sources, incrementing in each subsequent step
the frequency of the sources, but not their amplitudes or phase angles. HFS on the other hand,
performs harmonic analysis by executing a string of phasor solutions determined by a list of type14 sources entered by the user. This procedure is the same as the procedure for harmonic analysis
used by all commercial harmonic analysis software. The main advantage of this approach
compared with the time domain harmonic analysis is a reduction in runtime of ten times or more,
and avoidance of accuracy problems with Fourier analysis.
Models developed for HFS analysis using ATP are:
Frequency-dependent R-L-C elements
Frequency-dependent load based on the CIGRE type C model [4]
Harmonic current/voltage sources with frequency-dependent amplitude and phase.
Load Flow Option (FIX SOURCE)
This option adjusts the magnitudes and angles of sinusoidal sources iteratively in a sequence of
steady-state solution, until specified active and reactive power, or specified active power and
voltage magnitude, or some other specified criteria, are achieved. This will create the initial
conditions for the subsequent transient simulation.
EMTP Applications, Laboratory III, April – May,2001
Line/Cable models
Line Cable models in EMTP
The separate Line/Cable Constant supporting program ATP_LCC was on the prototype level
and contained some bugs and inconsistencies. The latest development resulted significant
change in the LINE/CABLE CONSTANTS support. The process of creating a line/cable
models in ATPDraw via the program ATP_LCC, needed several steps. This complicated the
usage and resulted in some extra work when modifying the model.
To use the built-in line/cable module of ATPDraw the user must first select a line/cable
component with the desired number of phases (1..9) under Line/Cable item in the selection
menu. This will display a component in the circuit window which is connected to the circuit as
any other component. Clicking on this component will bring up a special input dialog box
called the Line/cable dialog as shown in Fig. 1.
When the required data are specified the user can close the dialog by clicking on OK. This will
store the specified data to disk and run ATP to produce the required punch and lib files.
Fig. 1 - Line/Cable dialog window
In the Line/cable dialog the user can select
System type:
Overhead line: LINE CONSTANTS
Single core cables: CABLE PARAMETERS
Enclosing pipe: CABLE PARAMETERS
Model:
Bergeron: Constant parameter KCLee or Clark models
PI: Nominal PI-equivalent (short lines)
JMarti: Frequency dependent model with constant transformation matrix
Noda: Frequency dependent model
Semlyen: Frequency dependent simple fitted model
21
EMTP Applications, Laboratory III, April – May, 2001
Typical EMTP studies
Typical EMTP studies
The ATP version of the Electromagnetic Transients Program (EMTP) is an effective and
widely-used tool for simulating high-speed transients in electric power systems. ATP modelling
capabilities cover electromagnetic and electromechanical oscillations spanning the frequency
range from mHz to MHz. The EMTP is used worldwide for switching and lightning surge
analysis, insulation coordination, shaft torsional oscillations, protective relay modelling,
harmonics and power quality studies, HVDC and FACTS models. Because of its widespread
acceptance and use, it can be considered to be a standard analysis tool.
ATP has extensive modelling capabilities and additional important features besides the
computation of transients. It is out of scope of this report to give a complete collection of
engineering problems where ATP could be applied. Without completeness, some typical
application fields are listed below, and some examples are given.
Typical EMTP studies are:
- Lightning studies
- Switching transients and faults
- Statistical and systematic studies
- Very fast transients in GIS and groundings
- Machine modelling
- Transient stability studies, motor startup
- Shaft torsional oscillations
- Transformer and shunt reactor/capacitor switching
- Ferroresonance
- Power electronics applications
- Circuit breakers and arc, current chopping
- FACTS devices
- Harmonic analysis
- Frequency scans of network impedances
- Protective device testing
The following examples show how to use ATP for real engineering problems in the field of line
energization and fault studies, lightning studies or for transformer inrush transients simulations.
1 Single-line to ground fault on a 750 kV line (Lab01.adp)
A single-line to ground fault on a 750 kV interconnection are investigated in this study. In this
example the usage of the Line/Cable objects in combination with transposition objects are
demonstrated. The one-line diagram of the simulated network and the equivalent ATPDraw
circuit is shown in Fig. 1.1 Three transposition points exist along the route, the Overhead Line
objects represent line sections between transpositions.
22
EMTP Applications, Laboratory III, April – May, 2001
400
400 kV
kV
10000
MVA
6000 MVA
Typical EMTP studies
750 kV
1100 MVA
Single phase
to ground fault
∆
6000 MVA
750 kV tr. line
478 km
750
3
∆
1100 MVA
a) one-line diagram of the simulated network
b) ATPDraw circuit
Fig.1.1 - Single phase-to-ground fault study (Lab01.adp)
The Line/Cable Constant support is integrated part of ATPDraw program, so calculating the
electrical parameters of the line (and running a JMarti Setup run in the background) are all
automated. The line configuration is shown in Fig. 1.2.
13.2 m
At tower = 41.05 m
Midspan = 26.15 m
17.5 m
At tower = 27.9 m
Midspan = 13.0 m
Separ=60 cm
Alpha=45 °
NB=4
Fig. 1.2 - Tower configuration of the 750 kV line
The supply side networks connected to the 750 kV transmission line at the sending end and at
the receiving end are rather simple. Only the positive sequence short circuit impedance has
been taken into account by 3-phase RLC objects, connected parallel with a resistor
representing the equivalent surge impedance seen from the terminals. An uncoupled series
23
EMTP Applications, Laboratory III, April – May, 2001
Typical EMTP studies
reactance represents the short circuit inductance of the transformer bank consisting of three
single-phase units. The shunt reactors, -which are also single-phase devices- have been
represented by linear RLC components, because the amplitude of the reactor voltages are
below the saturation level of the air gapped core. The arc resistance of the fault is assumed to
be constant, and was approximation by a 2 ohms resistance.
Results of the simulation are shown in Fig 1.3.
2.500
*10 6
1.875
1.250
0.625
0.000
-0.625
-1.250
-1.875
-2.500
0.0
0.1
(file Cours99c.pl4; x-var t) v:SENDA
v:SENDB
0.2
v:SENDC
0.3
0.4
0.5
0.3
c:SENDC -LN1C
0.4
0.5
5000
4000
3000
2000
1000
0
-1000
-2000
-3000
0.0
0.1
(file Cours99c.pl4; x-var t) c:SENDA -LN1A
0.2
c:SENDB -LN1B
Fig. 1.3 - Calculated sending end voltages (above) and line currents (below) when single
phase-to-ground fault appers at the receiving end terminal
2
Lightning overvoltage study (Lab02.adp)
This example demonstrates how to use ATPDraw effectively in a substation lightning
protection study. Fig. 2.1 shows the one-line diagram of the cable connected 120 kV
substation.. The simulated incident is a single phase backflashover on the line arising 0.25 km
from the cable terminal. The simplified, single phase simulation model is shown on Fig 2.2.
24
EMTP Applications, Laboratory III, April – May, 2001
Typical EMTP studies
CSEPEL II
70m
50m
Zno korlátozó
FOJTÓ
Megszakító
Kábel
SOROKSÁR
HFKV
Szabadvezeték
4.2km
8.5km
4.4km
8.5km
Fig 2.1 Network connection of Csepel II Power Plant
KABL
CSEP
HFKV
2.86mH
FOJ
TRAF
25.5mH
4.2km
50m
188uF
a) simplified single phase diagram
VCSP
KABL C S E P H F KV FOJ
TRAF
b) ATPDraw simulation model (Lab02.adp)
Fig. 2.2
Fig. 2.3 shows the protection characteristics of metal-oxide arresters.
25
EMTP Applications, Laboratory III, April – May, 2001
Typical EMTP studies
400000
350000
300000
250000
U [V]200000
SB 102/10.2
Exlim R108
HSR 108
Pexlim 108
150000
100000
50000
0
1E-3
10E-3 100E-3
1E+0
10E+0 100E+0 1E+3
10E+3 100E+3
I [A]
Fig. 2.3 – U-I characteristics of some 120 kV ZnO arresters
Fig 2.4 shows a typical simulation result obtained with the following assumptions:
- the lightning hits the line 258 m before the cable junction
- zno arrester at both terminals
600
500
400
300
200
100
0
-100
-200
0.00
0.05
(file sorcsep.pl4; x-var t) v : K A B L
*10 -3
0.10
v:CSEP
0.15
v:FOJ
v:TRAF
0.20
0.25
0.30
Fig. 2.4: Voltage stresses at the cable terminals and at the step-up transformer
3 Modelling transformers with hysteresis (Lab03.adp)
When energising transformers, very often a transient magnetising inrush current occurs. This is
caused by the fact, that the flux in the iron core can not be changed abruptly. The phenomena
is easier to understand in a single phase transformer. At the zero crossing of the power
frequency voltage the magnetising current and the flux have their maximal values, and delay
with 90 electrical degrees. To satisfy the principle of the flux steadiness, it is necessary to build
an equalising flux with the same magnitude, but opposite polarity, in order to start the flux
from the remanent flux, as a starting point. The resultant flux reaches its highest value after a
half period, which can be significantly higher then the saturation point of the iron core. This
excess of flux is diverted to the coil system around the iron core (as it is written in the technical
literature into the „air”, which is not fully exact), where it can be kept only with high current
value. The transient current, which is generated in this way, is damped very slowly, and its
26
EMTP Applications, Laboratory III, April – May, 2001
Typical EMTP studies
highest value can be close to the short-circuit current of the transformer, causing dangerous
dynamic and thermal stresses.
3.1
Physical explanation of the inrush current
When the transformer is energized at the zero crossing of the voltage, with no remanent flux
present, the equalising flux has the same magnitude but opposite polarity as compared to the
highest operational flux. The resultant flux reaches the double of the normal operational flux
(nominal flux), which saturates the iron core. To keep the flux in the air, the inrush current
reaches the range of the rated current of the transformer. If the transformer is energised at
the peak value of the voltage with remanent flux equal zero, the transient current does not
exceed the steady state magnetising current of the transformer.
The phenomena in three-phase transformers are more complicated because of the galvanic and
magnetic connection between the phases. The amplitude of inrush current is depend on many
factors including the type of the iron core, the connection of the individual phases and the way
of neutral grounding.
When the switching operation starts with the central phase B at the voltage maximum of this
phase, the circuit is closed through the earth and the magnetic flux is formed without
transients. The magnetising current of the energised phase excites the open phases A and C to
the 50% of the steady state value. The flux of phases A and C reaches the values according to
the steady state momentary value after 5 ms, so at this moment both phases could be switched
on without high inrush current.
3.2 Calculation of the inrush current using hand-book formulas
The peak value of the inrush current is determined by the type of the iron core, the magnetic
parameters of the iron material and the construction of the coil system. High peak value
resultsin if the flux produced by the excitation voltage is added to the remanent flux with the
same polarity.
The maximal inrush current can be calculated with the following formula:
1 Av l
im =
⋅
⋅ ⋅ ( 2 ⋅ Bn + Br − Bt ) ,
µ 0 Al N
where
−1
µ 0 = 4 ⋅ π ⋅ 10 −7 Vs( Am) , the permeability of the air (oil)
Br the remanent induction,
Bn the peak value of the rated induction in the iron core
Av the cross section of the iron core
Al cross-section of the air ,
Bt saturation induction,
N is the number of turns in the energised coil,
l is the length of the magnetic flux curve in the air
The less favourable case of transformer energising is, if the switching on happens at the
zero crossing of the network voltage and at the remanent flux has its maximal value with the
polarity equivalent with the sign of the derivative of the voltage time function.
27
EMTP Applications, Laboratory III, April – May, 2001
Typical EMTP studies
The calculation method presented before includes some simplifications:
a) it supposes that the feeding network is infinite. In the reality the voltage at the
transformer is not independent on the magnitude of the current flowing into the
transformer. In real cases the supply voltage decreases considerably at the transformer
terminal point, if the current increases to the value higher than the rated current because
of the saturation, which acts against the further increase of the current.
b) the simplified method of calculation neglects the losses, however its effect to the first,
highest peak current is really not considerable.
c) the calculation neglects the multiphase properties of the transformer.
3.3
Modelling the iron core
The magnetizing branch of the transformer can be represented by a hysteretic nonlinear
inductor. ATP-EMTP supports only one type of magnetic material, but it could be used as first
approximation for other oriented silicon steel materials. Fig 3.1 shows the hysteresis loop of
the magnetic core of the transformer investigated in this study.
1.5
PSI [p.u.]
1
0.5
I [%]
0
-2
-0.5
-1
-1.5
-1
-0.5
0
0.5
1
1.5
2
Hyst+
HystArmco
-1.5
Fig. 3.1 - The shape of the hysteresis loop of the transformer
Beside the 132/15 kV Wye/delta connected unit transformer, this model takes into account the
the capacitance of the 500 m overhead line connected directly to the 120 kV side of the
transformer. The ATPDraw model is drawn in Fig. 3.2.
Fig. 3.2 - ATPDraw circuit of the 120 kV study case (Lab03.adp)
28
EMTP Applications, Laboratory III, April – May, 2001
Typical EMTP studies
The transformer model is a three phase Ynd11 type coil configuration with non-linear
inductance containing hysteresis as well, according to the real transformers. The hysteresis
loop of the 155 MVA transformer has been simulated with Type-96 hysteretic inductances.
1 .0
[A]
0 .5
0 .0
- 0 .5
- 1 .0
0
10
20
30
(file C o u r s 9 9 j.p l 4 ; x-va r t) c : S U P L A - T R 1 3 2 A
c:SU P L C -TR 1 3 2 C
40
[m s ]
50
c:SU P L B -TR 1 3 2 B
Fig. 3.3 - Calculated steady magnetizing current
120
[kV]
80
40
0
-4 0
-8 0
-1 2 0
0 .0 8
0 .0 9
(file C o u rs 9 9 j.p l 4 ; x-va r t) v:TR 1 3 2 A
0 .1 0
0 .1 1
v:TR 1 3 2 B
[s ]
0 .1 2
v:TR 1 3 2 C
Fig. 3.4 – Transformer phase voltages at a subsequent energization
close to the zero crossing of phase A
4000
[A]
2000
0
-2000
-4000
0 .0 8
0 .0 9
0 .1 0
0 .1 1
( f i l e C o u r s 9 9 j.p l 4 ; x-va r t ) c : S U P L A - T R 1 3 2 A
c:S U P L C -TR 1 3 2 C
0 .1 2
0 .1 3
0 .1 4
[s ]
0 .1 5
c:S U P L B - T R 1 3 2 B
Fig. 3.5 - Calculated inrush current
29
EMTP Applications, Laboratory III, April – May, 2001
Typical EMTP studies
Mérési feladatok
Otthoni, elõkészítõ feladatok:
1. Készítse el a Lab02.adp hálózat ( 2.2/a ábra) koncentrált R-L-C elemekbõl összeállítható
helyettesítõ áramkörét. A távvezeték és a kábel hullámimpedanciája 400, ill. 40 ohm.
2. Számítsa ki a 3.2 ábrán felrajzolt 120/15 kV-os transzformátor (Lab03.adp hálózat)
bekapcsolási áramlökésének maximális értékét. A transzformátor adatai az alábbiak:
Rated voltage: 132 ± 5% / 15 kV
Rated current: 678 / 5966 A
Rated power: 155 MVA
Connection: Ynd11
Short circuit reactance: 14 %
Magnetising current: 0.3 / 2.67 A
Cross section of the iron core: Av = 0.535 m2
Cross section of the air channel between the iron core and high voltage core Al = 1.21 m2
Number of the energised turns in case of tap changer position -5%: N = 375
Rated induction: Bn = 1.62 T
Remanent induction: Br = 1.52 T (75% of the saturation induction)
Saturation induction: Bt = 2.03 T
Length of the flux line in the air: l = 2 m
Mérési feladatok:
1. mérõcsoport : A + B feladatsor
2. mérõcsoport: A + C feladatsor
A mérés végén a mérõcsoportok az önállóan elvégzett B és C mérés eredményeirõl 10 perces
elõadás keretében számolnak be a másik csoport tagjainak és a mérésvezetõnek.
A.1. A Lab01.adp fájl felhasználásával határozza meg a terheletlen 750 kV-os vezeték
végpontján fellépõ feszültségemelkedés mértékét állandósul állapotban
0, 2 ill. 3 söntfojtókészlet bekapcsolt állapotát feltételezve.
A.2. A Lab01.adp hálózaton határozza meg a nyitott vezetékvégen kialakuló bekapcsolási
túlfeszültséget a fázisfeszültség-maximum pillanatban történõ bekapcsolás esetén.
B.1. A Lab02.adp fájl felhasználásával határozza meg a hálózaton beépítendõ
korlátozókészletek számát és optimális elhelyezését úgy, hogy a feszültség a hálózat
egyetlen pontján se haladja meg a 120 kV-os berendezések próbafeszültsége (550 kV)
80%-át.
B.2. Ellenõrizze az otthoni felkészülés során kiszámított helyettesítõ áramkör jóságát. Vesse
egybe a túlfeszültségvédelem nélküli Lab02.adp hálózat és a helyettesítõ áramkör azonos
pontjain mért feszültséglengés amplitudóját és frekvenciáját.
C.1. A Lab03.adp hálózat felhasználásával határozza meg a transzformátor-fázisok remananes
fluxusát a kikapcsolás idõpillanatának függvényében. A megszakítópólusok kikapcsolási
sorrendje CB - A, (0+x)(0+x) - (5+x) ms.
C.2. Határozza meg a legkisebb és a legnagyobb áramlökést eredményezõ bekapcsolási
pillanatot, a fenti A-CB (0-5-5 ms) bekapcsolási sorrendû megszakí tó alkalmazása esetén
a remanens fluxus elhanyagolásával, illetve figyelembe vételével.
30